Charlie Brooker is certainly right that we remember eras in cinematic style (What is the difference between The Hobbit and the news? Not as much as there should be, G2, 30 April), and he could even push this back to the frozen monochrome of Victorian photography. But why does he have to spoil it by blaming the hand-cranked cameras of the 1920s for speeded-up footage from that period? Many cameras – though not all – were hand-cranked, and deliberately at different rates, and what they filmed was shown at different speeds too, until the talkies imposed a standard projection rate of 24 frames per second. When we see speeded-up footage today, this is because whoever transferred it couldn't be bothered to adjust the transfer rate – or thought it looked quaint not to. And when Brooker evokes "lush Eastmancolor", I suspect he means late Technicolor, which was certainly lush compared with its cheaper replacement that has now mostly faded to pink.Ian ChristieBirkbeck, University of London